Method and device for treatment of varicose veins

ABSTRACT

A method and device for treatment of a varicose vein is provided which includes the step of applying to the skin of a subject superficial to the vein to be treated a device including: (a) an element for securing the device to the leg of a subject superficial to the vein to be treated such as a carrier tape; and (b) a one-way valve element such as a cantilever element biased by a spring for applying a selected amount of pressure to the skin superficial to the vein to be treated in a manner such that blood-flow toward the heart is permitted during peripheral venous pumping but wherein backflow away from the heart as a result of gravity is substantially reduced; and applying sufficient pressure to the skin superficial to the vein to be treated in a manner such that blood-flow toward the heart is permitted during peripheral venous pumping but wherein backflow away from the heart as a result of gravity is substantially reduced.

This is a divisional of U.S. application Ser. No. 09/036,164, filed Mar.6, 1998 now U.S. Pat. No. 6,074,356.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to the medical treatment of varicoseveins, and more specifically to a non-invasive, topical treatment forvaricose veins utilizing the device described herein to act as anexternal one-way valve to replace the function of the defective internalvalves contained within the varicose veins to be treated. Thisnon-invasive treatment improves blood flow in the varicose veins anddiminishes the vein varicosities without the necessity for an invasiveand costly surgical procedure, the scarring which often resultspost-operatively from such procedures, the recurrence of varicositieswhich often follows such procedures, or the other undesirable effects ofpresently available treatments for varicose veins. This non-invasivetreatment differs from other available treatments in that unlike suchtreatments, it restores rather than obliterates venous function.

2. Description of Varicose Vein Treatments and Related Art

Varicose veins is a medical condition which involves the abnormaltwisting, lengthening or dilation of the superficial veins of the leg.It has been estimated that between 20% to 30% of the adult populationsuffers from some form and degree of varicose veins. Significantvaricosities, those which are large enough for treatment, have beenestimated to occur in about 12% of the adult population. Patientssuffering from varicose veins often suffer from a variety of symptomsincluding aching, swelling, burning, throbbing and cramping in andaround the areas in which the varicosities exist. These symptoms arefelt much more intensely by women during pregnancy or during or justbefore menstruation. One survey showed that 50% of persons with varicoseveins were bothered by their symptoms occasionally, and that 18% notedfrequent to continuous symptoms. More serious complications may alsoresult from the presence of varicose veins including phlebitis,ulceration, eczema, dermatitis and two-fold to four-fold increased riskof deep vein thrombosis. Even in the absence of such symptoms or moreserious complications relating to the varicosities, many varicose veinsufferers seek medical treatment for the condition due to unsightlinessof the varicosities.

The venous system of the legs consists of two channels: one deep withinthe muscular system and one superficial to it. The deep veins and thesuperficial veins are connected through a series of communicating veins,also called perforating veins. The superficial veins function mainly tocollect blood from the subcutaneous tissue and to carry it to theclosest communicating vein for rapid transit through the deep veins backto the heart. Approximately 15% of the venous blood volume in the legsis contained in the superficial veins, with 85% in the deep vein system.

One-way, bicuspid valves are located in the superficial veins that, whenproperly functioning, permit unidirectional flow of blood from thesuperficial venous system into the deep system to permit proper andrapid transmission of blood to the heart. These valves also break-up theotherwise continuous column of blood leading to the heart and thusreduce the hydrostatic pressure on the veins.

The cusps of the superficial venous valves are attached to the walls ofthe veins. Due to defective structure or function of the valves withinthe saphenous veins, intrinsic weakness of the vein walls, or theeffects of a traumatic event which has significantly increased the bloodpressure in the superficial veins (pregnancy being by far the singlemost significant such event), the valves of the saphenous veins becomeincompetent, permitting bidirectional flow (backflow or reflux) of bloodthrough the veins with a corresponding increase in retrograde pressurein such veins. Regardless of the original cause of the valveincompetency, the result is the enlargement of the saphenous veinswhich, lying close to the skin and being poorly supported by thesubcutaneous tissue, become varicose.

Once valve incompetence occurs, such as at valves on the upper thighnear the saphenous junction, and as blood refluxes, further venousenlargement occurs upstream (i.e., away from the heart and toward thefeet), pulling the valve cusps further apart, causing more valvularincompetence in sections of the adjacent distal vein. As the segment ofthe engorged saphenous vein becomes elongated, the hydrostatic pressureexerted by the uninterrupted column of blood increases, furtherexacerbating the condition which causes the varicosities. With time,this process propagates into peripheral venous branches and also intocommunicating veins when they become exposed to the increased pressurefrom the continuous column of blood below an incompetent valve in themain saphenous channel. Moreover, in this condition, blood pressureduring exercise fails to decrease normally because effective valves arenot present.

Ebers in the papyrus of 1550 B.C. first described the condition ofvaricose veins and advised that surgery should not be performed. CaiusMarius in Plutarch's Lives underwent surgical correction of the varicoseveins in one of his legs, but when questioned regarding similartreatment for the other leg, declined by noting, “I see the cure is notworth the pain.” For more than three thousand years, suffers of varicoseveins have wrestled with the problem, attempting to avoid surgicalrepair of the condition while seeking less intrusive and more effectivemanagement methods for the condition.

There are currently three known types of treatment for varicose veins:(1) surgical vein ligation or stripping; (2) sclerotherapy: and (3)compression therapy. Surgical therapy in the form of vein stripping isdirected at ligating the varicose system at its origin and removing theveins to prevent persistent reflux by direct and collateral routes. Inthe stripping technique, a small incision is placed at the distal end ofthe vein near the groin. The saphenous vein is also ligated at the foot.An internal vein stripper is then advanced proximally through theincision at the groin and secured. The stripper is then gently removedthrough the incision at the groin. It is also necessary for the surgeonto make multiple small incisions along the leg in order to disconnectthe numerous communicating veins from the saphenous vein and to ligatethese communicating veins. Postoperatively, the leg is wrapped andambulation is held to a minimum for 8 to 12 hours. Complete recoveryfrom varicose vein stripping usually takes 2 to 3 weeks. While saphenousvein stripping can often be accomplished without the use of a generalanesthetic and without overnight hospitalization, particularly with theadvent of ambulatory phlebectomy, a European developed varicose veinstripping procedure, a spinal or epidermal anesthetic is required.Surgical treatment of varicose veins may also be accomplished by veinligation alone. While this procedure may be cost effective, studies haveshown that it may not yield positive long term results due to extremelyhigh rates of recurrence.

While stripping techniques represent a permanent solution in the areawhere the removed veins existed, the technique has numerous drawbacks.First, recurrence can occur in other areas of the leg away from theremoved veins, and studies have shown recurrence rates from 12 to 56%over a five year period for patients who underwent vein stripping.Second, the procedure results in scarring which may be as cosmeticallyunsatisfactory as the varicose veins themselves. Third, a variety ofcomplications can result from the procedure including infection,cutaneous pigmentation, superficial thrombophlebitis, deep venousthrombophlebitis, and nerve injury. Finally, if the veins are removed,they are unavailable should they be needed for arterial reconstruction,since the saphenous veins are normally used in such procedures.

Sclerotherapy involves injecting a liquid into the varicose veins thatinduces inflammation and scarring or sclerosis sufficient to seal thevein closed, which forces blood flow away from the affected veins.Various methods of sclerotherapy involve differing sclerosing agentscombined with various levels of compression therapy to optimizeefficacy.

In general, after careful mapping of the involved veins, a small gaugeneedle on a syringe containing the sclerosing agent is inserted into thevein while the leg is dependent. The syringe is taped to the leg whiletwo or three other veins are punctured in the same manner. The leg isthen elevated to empty the veins and the sclerosing agent is applied ateach site. At the completion of the injections, a firm elastic bandageis wrapped carefully from the foot to 6 inches above the most proximalinjection site. Some physicians recommend continuous compression for aslong as 6 weeks. After compression has ended, the patient returns to thephysician's office for removal of the bandages and inspection of theresults. Further injections can then be made, and the cycle can berepeated until the varicosities are gone.

While sclerotherapy is less expensive than vein stripping or ligationand is less invasive than such surgical procedures, it also has severedrawbacks. First, since it does not involve the removal of the affectedveins, sclerotherapy may not represent a permanent or completemanagement technique. Studies have shown that the five year recurrencerate in small superficial or lower-leg communicating veins was 19%,while recurrence over that same period in large main venous trunks was69%. Second, various complications can arise from the therapy, thoughmost are minor and severe complications are rare. Third, it is oftennecessary for patients to undergo multiple courses of therapy to obtainsufficient results. Finally, as with stripping of the veins,sclerotherapy makes the veins unavailable for use in subsequentreconstructive procedures.

Finally, varicose veins may be “conservatively” managed by theemployment of compression therapy. Compression of the varicose veinoccludes the vein, eliminating temporarily not only backflow of bloodthrough the vein away from the heart but also flow in the normaldirection toward the heart. Among compression measures, the most commonis the elastic stocking, numerous brands and styles of which arecommercially available and which are widely described in the literaturesuch as by Lubin, U.S. Pat. No. 366,590; Teufel, U.S. Pat. No. 967,585;Scholl, U.S. Pat. No. 2,646,797; Westlake, U.S. Pat. No. 4,513,740;Daneshvar, U.S. Pat. No. 5,520,630; Fujimoto, U.S. Pat. No. 5,263,923;and Arabeyre et al. U.S. Pat. No. 5,497,513. While compression therapyis non-invasive, and therefore less painful than surgery orsclerotherapy, and considerably less expensive than such treatments,compression stockings are uncomfortable (particularly in warm weather),often don't provide the desired effect and are as unsightly as thevaricose veins to be treated.

Also known in the art is a variation on compressive therapy whereby avaricose vein is occluded by means of a tourniquet-like leg wrapping.Schutz et al., U.S. Pat. No. 519,894 discloses a strap for treatment ofvaricose veins whereby sufficient pressure is applied to a varicose veinso as to prevent retrograde blood flow (backflow) but which alsoprevents flow of blood in the normal direction toward the heart as aresult of peripheral venous pumping caused by the action of the majormuscles in the leg.

Compression therapies, focusing on the utilization of stockings ofvarying external compression can be useful in providing temporaryrelief, particularly to pregnant women in the third trimester ofpregnancy but are normally ineffective as a long term treatment for thereasons stated above. Moreover, when compressive therapies providesufficient pressure to prevent “backflow,” they also prevent thebeneficial flow of blood in the desired direction toward the heart.

The prior art relating to the treatment of varicose veins specificallyand the use of pressure to treat venous and other ailments in general isdirected to the simple concept of venous occlusion or removal torestrict venous blood flow to the exclusion of proper venous function.Ligation, stripping, and scierotherapy permit treatment of the varicosevein by its pennanent destruction and are inconsistent with therestoration of proper venous function. Compression therapy whileattempting to accomplish a similar goal as more permanent varicose veinmanagement measures are nevertheless temporary and are equallyantithetical to restoration of venous function.

Given the severe drawbacks which exist in all of the presently availabletreatments for varicose veins, and in light of the historic search foran acceptable, non-invasive treatment for this condition, it is plainthat a critical need exists for alternative treatments. Moreover, andperhaps of equal importance is the need for an effective treatmentalternative which focuses on restoring proper venous function, ratherthan focusing on the obliteration or removal of the venous structures orthe negation of their proper function.

SUMMARY OF THE INVENTION

The present invention provides improved methods and devices for thetreatment of varicose veins wherein the function of the one-way valvesin the varicose vein is replaced or supplemented by means of a deviceaccording to the invention which applies external pressure to thevaricose vein in a manner which allows for flow in the normal directiontoward the heart as a result of peripheral venous pumping butsubstantially reduces backflow away from the heart due to gravity.Specifically, the invention provides a device for treatment of avaricose vein of a subject comprising: (a) means for securing saiddevice to the leg of a subject superficial to said vein to be treated;and (b) means for applying a selected amount of pressure to the skinsuperficial to said vein to be treated in a manner such that blood-flowtoward the heart is permitted during peripheral venous pumping butwherein backflow away from the heart as a result of gravity is reduced.According to a preferred embodiment, a base which supports the means forapplying pressure is attached to said securing means wherein the base iscapable of traversing the skin superficial to said vein to be treated ina manner in which substantial downward pressure is not applied by thebase to the skin superficial to said vein to be treated.

According to one embodiment of the invention, the means for applyingpressure is a cantilever element such as a hinged strip of plastic whichis attached to the base and which is biased by means such as a springagainst the skin superficial to the vein to be treated. The biasingmeans is preferably a spring extending from the base which spring exertsforce on the cantilever element which displaces the proximal wall of thevein toward the distal wall to form a junction closing the vein.According to one aspect of the invention, the cantilever element extendsfrom the base in a direction toward the heart and exerts pressure on thevein at an angle such that venous pressure on the side of said junctiondistal from the heart exerts greater effective force displacing saidstrip than does venous pressure on the side of the junction proximal tothe heart. In this manner, pressure on the valve resulting fromperipheral venous pumping by contraction of the leg muscles such asoccurs during walking will open the valve allowing blood to flow towardthe heart. However, the pressure exerted against the cantilever elementcaused by the gravitational force on the head of the column of bloodbetween the heart and the cantilever element of the invention willordinarily be insufficient to displace the cantilever element and allowsubstantial backflow (retrograde flow) down the vein.

According to an alternative embodiment, the means for applying pressureis in the form of a wedge which can be biased against the skin by meanssuch as a spring or can be made of a resilient material which exertspressure against the skin. Such a wedge is preferably designed anddisposed in a fashion wherein the apex of the wedge displaces theproximal wall of the vein toward the distal wall to form a junctionclosing the vein and wherein the wall of the wedge on the side of theapex away from the heart is disposed at an angle from the plane of thevein which is less than the angle from the plane of the vein of thewedge wall on the side of the apex toward the heart.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a partly cutaway perspective of a preferred device foruse according to the invention,

FIG. 2 depicts a top view of the device of FIG. 1 with its coverremoved;

FIG. 3 depicts a side view of the device of FIG. 2;

FIG. 4 depicts an alternative device for use according to the invention;

FIG. 5 depicts another alternative device for use according to theinvention;

FIG. 6 depicts a further alternative device for use according to theinvention;

FIG. 7 depicts blood flow in a normal superficial saphenous vein withthe subject standing and flexing his foot;

FIG. 8 depicts blood flow in a varicose superficial saphenous vein withthe subject supine;

FIG. 9 depicts blood flow in a varicose superficial saphenous vein withthe subject standing; and

FIG. 10 depicts blood flow in a varicose superficial saphenous vein of astanding subject treated with a device according to the invention.

DETAILED DESCRIPTION

The devices of the invention preferably comprise (a) means for securingsaid device to the leg of a subject superficial to the vein to betreated; (b) means for applying a selected amount of pressure to theskin superficial to said vein to be treated in a manner such thatblood-flow toward the heart is permitted during peripheral venouspumping but wherein backflow away from the heart as a result of gravityis reduced; and (c) a base attached to the securing means capable oftraversing the skin superficial to the vein to be treated in a manner inwhich substantial downward pressure is not applied to the skinsuperficial to the vein to be treated wherein the means for applyingpressure is attached to the base.

The preferred means for applying pressure according to the invention isa cantilever element which is biased by a spring. The cantilever elementmay be produced from any of a variety of materials such as plastic andmetal and may be of a variety of shapes and configurations provided thatwhen biased against the skin superficial to a varicose vein, it providessufficient pressure so as to substantially reduce backflow down the veinaway from the heart while allowing flow resulting from peripheral venouspumping toward the heart. Cantilever elements useful according to theinvention are preferably but need not be of an elongated rectangularshape. The cantilever element may be biased toward the user's skin by aseparate spring mechanism mounted to the base or, alternatively, thespring or other biasing means may be integral with the cantileverelements. Any of a wide range of spring mechanisms well known in the artmay be used for this purpose including but not limited to simple orcompound springs of the compression type, the leaf type, the torsiontype or the extension type.

The bottom of the cantilever element may include a tip or otherwise beshaped to fit the profile of the collapsed vein and preferably will havea convex shape in the direction of the vein to be treated. The bottomportion of the cantilever element may be formed from or coated by aresilient material for comfort and to facilitate the formation of abetter seal when the valve is closed. Further, the means for applyingpressure to the skin may be treated with a medical type of adhesive tosecure a firm hold on the skin immediately superficial to the vein to betreated. Alternatively, the means for applying pressure may be treatedwith a low friction material to prevent binding with the skin.

If is preferred that the base be designed in such a way that itsurrounds the area of the vein to be treated on all sides and that themeans for securing the base to the skin be a medical type adhesivedisposed on the bottom face of the base. This arrangement isadvantageous in that it prevents the pressure exerted by the means forapplying pressure from excessively indenting the leg tissue bymaintaining a firm hold on the skin immediately adjacent to the area ofskin on which the cantilever element is pressing.

According to an alternative embodiment, the means for applying pressureis in the form of a wedge, the apex of which displaces the proximal wallof the vein toward the distal wall to form a junction closing said veinand wherein the wall of the wedge on the side of the apex away from theheart is disposed at an angle from the plane of the vein which is lessthan the angle from the plane of the vein of the wedge wall on the sideof the apex toward the heart. Preferably, the wedge wall on the side ofthe apex toward the heart is disposed at a right angle to plane of thevein. The wedge is preferably formed of a resilient material such asrubber or foam but may be a non-resilient material which is resilientlymounted on the base such as with an elastomer or may be biased by othermeans such as a spring. According to a preferred embodiment of theinvention, the wedge is disposed between a semirigid base and the veinto be treated.

The securing means of the invention may be any that will maintain thedevice in place on the skin of the wearer and superficial to thevaricose vein to be treated and which provides sufficient support forthe means for providing pressure to the vein. Accordingly, the means mayinclude adhesive means such as used with adhesive bandages or may bemeans such as garters or bands which encircle the leg. A preferredsecuring means of the invention is a carrier tape comprising a backingand a layer of pressure-sensitive adhesive on one surface of saidbacking which allows for convenient application of the device to anappropriate location on the subject to be treated. Alternative means forsecuring the device include bands and garters which encircle the leg aswell as combinations of adhesive means with such bands and garters.

While the preferred embodiments of the present invention can berelatively simple mechanical devices, more complex electromechanicaldevices are also contemplated wherein electronic means are used toaccomplish the objectives of the invention. In this expression of theinvention, an electronic pressure sensor is disposed over the varicosevein upstream from an electronically activated plunger that is disposedover the varicosity to be treated. When a venous pressure wave due tothe contraction of the calf muscles comes up the vein, it is detected bythe sensor which activates the electronically actuated plunger to riseand open and allow a bolus of blood to pass through going upward towardthe heart. When the pressure wave has passed, the sensor detects thereduced pressure in the vein and deactivates the plunger causing it toclose by pressing down on the intact skin directly overlying thevaricose vein. This action prevents backflow of blood and relieves thevein below the valve of excessive hydrostatic pressure in the samemanner as the mechanical valves described in other expressions of thisinvention.

The device includes a battery to provide power to the valve and othercomponents of the device. The device may be mounted on a base whichenables it to be disposed over the varicose vein without applyingsignificant downward pressure to it except where the electronic plungerpresses down and closes the vein by external pressure. An electroniccontrol unit may be added to the device to provide additional timing andcontrol functions for the valve and additional sensors may be used toprovide more sophisticated control functions. Many types of electronicsensors can be used to sense the wave of pressure and blood coming upthe leg. These sensors include but are not limited to micro switches tosense deflection of the vein wall, other types of electronic pressuresensors, blood flow sensors of ultrasonic or other types of blood flowsensors using light to sense color changes associated with the passageof a bolus of blood. The plunger may be solenoid activated or be anytype of electronically controlled valve or plunger apparatus that canexert satisfactory pressure on the skin overlying the varicose vein.

According to methods of the invention, a varicose vein may be treated byapplying the device of the invention to the skin of a subjectsuperficial to the vein to be treated wherein the means for applyingpressure is located superficial to said vein to be treated with pressureapplied to the skin in a manner such that blood-flow toward the heart ispermitted during peripheral venous pumping but wherein backflow awayfrom the heart as a result of gravity is substantially reduced. While itis preferred that retrograde flow (backflow) be eliminated entirely,there still remain substantial therapeutic and cosmetic benefits to bederived by substantial reduction of the volume of backflow which isdefined as a reduction of 50 % or more. Preferably, the reduction inbackflow is greater than 75% and more preferably 90% or even 95%,although these higher levels of backflow reduction are not necessary tosuccessful practice of the methods of the invention. As another measureof the therapeutic utility of the present invention the ratio of forwardto retrograde flow is useful to determine the benefit conferred by themethods and devices of the invention. As such a 2:1 bias in flow towardthe heart is considered to be indicative of a successful result ofapplication of the inventive method and device. As the level of backflowis decreased, this bias ratio of flow toward versus flow away from theheart will increase such that bias ratios of 3:1, 5: 1, 10:1 and even50:1 and greater may be achieved.

According to one embodiment of the invention, the device is appliedsuperficial to the saphenous vein upstream (that is below or away fromthe heart) of the saphenous junction. Preferably the device is appliedsuch that pressure is applied immediately upstream of the saphenousjunction by which is meant within about 10 cm or more preferably 5 cmfrom the junction. In this manner, when the vein has become varicose asa consequence of failure of valves upstream of the saphenous junction,application of the device of the invention will substantially reducebackflow of the blood while allowing flow of blood toward the heart dueto peripheral venous pumping. When the device is applied in the vicinityof the saphenous junction, the means for applying pressure preferablyapplies from about 0.05 pounds force to about 2 pounds force (notpressure) and more preferably from about 0.2 to about 1 pound of forceto the skin superficial to the varicose vein. Most preferably, thedevices of the invention apply about 0.4 to about 0.8 pounds force tothe skin superficial to the varicose vein to be treated but the optimumamount of force required will vary according to the particularcharacteristics of the subject and the vein to be treated and the exactdimensions and configuration of the device and means used to applypressure to the skin. Nevertheless, those of ordinary skill whenprovided with the principles of this invention will be able to determineoptimum levels of force to be applied to treat the varicosities of anyparticular subject, recognizing general principles of design for examplethat pressure is a function of force divided by the area over which thatforce is applied. Nevertheless, for successful practice of the presentinvention force rather than pressure appears to be the more importantdesign consideration.

When a varicose vein is manifested by failure of valves within both theupper (e.g. saphenous) and lower (e.g. popliteal) portions of the leg,the device may also be applied lower on the leg alone or more preferablyin combination with one or more devices higher on the leg such as in thevicinity of the saphenous.junction. One particularly suitable locationfor placement of the device is superficial to the saphenous veinimmediately upstream of the popliteal junction by which is meant withinabout 5 cm from the junction.

When the device is applied in the vicinity of the popliteal junction,the force applied by the device will typically be somewhat greater thanthat required at the saphenous junction due to the greater fluid headforce at that location although the force required will depend on themany factors mentioned above and can be readily determined for any givensubject.

In FIGS. 1, 2 and 3 is depicted a preferred device 10 according to thepresent invention for treatment of varicose veins. Device 10 comprises abase 12 which is a circular piece of thin plastic such as moldedpolypropylene having a top disposed away from the wearer and a bottomdisposed toward the wearer. The base 12 can be planar or can be slightlycurved in order to conform to the back of a leg of a subject to whom itis applied. Integral with the base 12 is a hinged cantilever element 14having a tip 16 disposed toward the wearer for contacting the skinsuperficial to the vein to be treated. The tip 16 has a bottom surface18 and an end surface 20 which are disposed against the skin of thewearer during use of the device. The base 12 further includes a pair ofmolded spring mounts 22 to which a spring 24 is disposed which biasesthe cantilever element 14 toward the wearer.

Disposed on the bottom surface (wearer side) of the base 12 is anadhesive coating (not shown) which is capable of securing the device tothe leg of a subject. The adhesive coating can be applied exclusively tothe bottom surface of the base 12 excluding the cantilever element 14.Alternatively, the bottom surface 18 of the tip 16 may also have anadhesive backing disposed thereon which will assist in securing the skinto the tip and will reduce the tendency of the skin surface to “roll”away from the tip 16 upon application of pressure. The device 10 furthercomprises a nonstick backing 26 on its bottom which covers the adhesivecoating until it is applied for use. The device 10 also comprises acover 28 (shown partly cut-away) which is preferably a thin plastic filmwhich protects clothing from entangling with elements of the device 10and further improves the aesthetics of the device 10 and its appearanceunder clothing.

FIG. 3 depicts the device 10 in cross-section along line A—A and depictsthe cross-section of the cantilever element 14 having a tip 16 forapplying pressure by contacting the skin of the wearer superficial tothe vein to be treated. According to one preferred, embodiment of theinvention as depicted in FIG. 3, the tip 16 of the cantilever element 14is shaped such that when it extends from the base 12 in a directiontoward the heart it exerts pressure on the varicose vein to be treatedat an angle such that venous pressure on the side of the junction awayfrom the heart exerts greater force displacing the cantilever elementthan does venous pressure on the side of the junction nearer the heart.Thus, venous pressure created by peripheral venous pumping will applyforce against a large surface area of the gently sloping bottom 18 ofthe tip 16 on the cantilever element 14 and will relatively readilydisplace the cantilever element 14 in response to venous pumping.

In contrast, the retrograde force created by the gravitational head ofvenous fluid above the device 10 will primarily be applied against theend 20 of the tip 16. Because the force vector against the tip 16 issubstantially normal to the surface of the end 20 of the tip 16, thatforce will not tend to displace the cantilever element 14 so as to allowsubstantial retrograde flow. The device 10 may be applied by means ofadhesive to the leg of the wearer superficial to the vein to be treatedsuch that the end 20 of the tip 16 is disposed along the flow path ofblood toward the heart of the wearer. In this manner the pressureexerted by the biased cantilever element 14 on the varicose vein willallow forward flow of blood toward the heart caused by peripheral venouspumping but will substantially reduce retrograde flow (backflow) causedby gravity away from the heart.

FIG. 4 depicts an alternative device 30 according to the invention whichcomprises a base 32 which can be fabricated from a suitable materialsuch as polypropylene or other plastic and can comprise an adhesivebacking for application to the leg of the wearer. Disposed on the base32 is a cantilever element 34 which is an arcuate shaped finger and isconvex toward the wearer and is fabricated such that it is integrallybiased toward the bottom (wearer side) of the base 32. The cantileverelement 34 has a gently sloping bottom 36 and a substantially flatcrescent shaped tip 38 at its end. The device 30 may be applied by meansof adhesive to the leg of the wearer superficial to the vein to betreated such that the tip 38 is disposed along the flow path of bloodtoward the heart of the wearer. In this manner the pressure exerted byperipheral venous pumping will readily displace the cantilevered finger34 on the varicose vein to allow forward flow of blood toward the heartbut the retrograde force caused by the gravitational head of venousfluid above the device 30 will primarily be applied against thesubstantially flat crescent shaped tip 38 at its end and thus will nottend to displace the cantilever element 34. In this manner, retrogradeflow (backflow) away from the heart caused by gravity is substantiallyreduced while forward flow toward the heart is not substantiallyimpeded.

FIG. 5 depicts a further alternative embodiment which furtherillustrates the variations which can be made in practice of theinvention. This alternative device 50 comprises a base 52 which ispreferably fabricated from plastic and is substantially planar or isslightly curved in order to conform to the leg of the user. The device50, further comprises means for securing the device 50 to the leg of theuser which comprises an adhesive bandage 54. The adhesive bandage 54 canattach adjacent to the sides of the device 50 or alternatively canencircle the leg of the user. Where the means for securing the device 50encircles the leg of the user, the adhesive bandage 54 can besupplemented or even replaced by other securing means such as by hookand loop fasteners such as those marketed under the trademark Velcro®.Within the center of and integral with the base 52 is disposed acantilever element 56 for contacting the skin superficial to thevaricose vein to be treated having a gently sloping bottom (not shown)similar to that of the device 10 of FIG. 3 and a tip 58. Disposed on theupper side of the base (away from the wearer) 52 and integral therewithis a spring mount 60 in which is mounted a spring 62 such as may beproduced from flat spring steel and which biases the cantilever element56 toward the wearer's body. In use, the alternative device 50 isapplied by means of adhesive to the leg of the wearer superficial to thevein to be treated such that the tip 58 is disposed toward the heart ofthe wearer (downstream). In this manner, the pressure exerted by thebiased cantilever element 56 on the varicose vein will allow forwardflow of blood toward the heart caused by peripheral venous pumping butwill substantially reduce backflow of blood away from the heart.

FIG. 6 depicts a further alternative embodiment device 70 comprising abase member 72 having a semi-cylindrical shaped resilient foam wedge 74having a side portion 76 and an end portion 78 disposed on its bottomside (towards the wearer) which is preferably fabricated from plasticand is substantially planar or is slightly curved in order to conform tothe leg of the user. The device further comprises means for securing thedevice to the leg of the user which can be an adhesive backing appliedto the bottom surface of the base 72. The resilient foam wedge 74 isshaped such that when it extends from the base 72 in a direction towardthe heart its side portion 76 exerts pressure on the varicose vein to betreated at an angle such that venous pressure on the side of thejunction created by the exertion of pressure away from the heart exertsgreater force displacing the resilient foam than does venous pressure onend portion 78 on the side of the junction nearer the heart. Thus venouspressure created by peripheral venous pumping will apply force against alarge surface area of the gently sloping side portion 76 of the foamwedge and will relatively readily displace the resilient foam inresponse to venous pumping in order to allow flow in the proper forwarddirection. In contrast the retrograde force created by the gravitationalhead of venous fluid above the device will primarily be applied againstthe end portion 78 of the foam wedge. Because the force vector againstthe end 78 is substantially normal to its surface that force will nottend to displace the end of the foam wedge so as to allow substantialretrograde flow. In this manner, retrograde flow away from the heartcaused by gravity is substantially reduced while forward flow toward theheart is not substantially impeded.

EXAMPLE

According to this example a device according to the invention andgenerally corresponding to the device of FIG. 1 was used to treat asubject having a varicosity in his superficial saphenous vein whileblood flow was measured under differing conditions using a Doppler flowsystem (Hokanson MD6). The blood flow in the varicose saphenous vein ofthis subject was compared to the blood flow in a properly functioningsaphenous vein of another subject. The Doppler flow probe was positionedover the vein and near the saphenous junction of the individuals' legs.FIG. 7 depicts the flow of blood in a normal, properly functioningsuperficial saphenous vein while the subject was standing and flexinghis foot. This figure shows blood flow in the forward direction towardthe heart (positive velocities on the y-axis) and no significantretrograde flow (negative velocities on the y-axis).

In contrast, FIG. 8 depicts the flow of blood in a varicose superficialsaphenous vein with the subject supine. In this figure, the blood flowsin an uncontrolled, bidirectional manner, going both forward (antegrade)and retrograde. FIG. 9 depicts the flow of blood in the same individualstanding while flexing his foot. The foot flexes produced spurts offorward flow followed by massive amounts of backflow. It appears thatthe blood from the inner saphenous vein was draining through theperforator into the superficial vein at a rate equal to or greater thanthe short spurts of forward flow. Overall, the flow was primarilyretrograde.

FIG. 10 depicts the effects of treatment with the device of theinvention on the subject with the varicose superficial saphenous veinwhile the subject was standing and flexing his foot. As shown in thefigure, retrograde flow was reduced to nearly zero and front flow wasrestored. While the flow signature of the positive blood flow velocitiesis different in shape from that of a healthy vein (due primarily to theincreased fluid volume contained in the stretched and elongated varicosevein), the positive flow direction indicates that the deficiencies ofthe varicose vein system have been compensated for. Flow reversal inFIG. 10 occurred at settings of 0.46 pounds force preload, with 0.029pounds/radian torsional spring constant with a rounded profile tipwhich, along with the base had been coated with adhesive.

Numerous modifications and variations in the practice of the inventionare expected to occur to those skilled in the art upon consideration ofthe foregoing description of the presently preferred embodimentsthereof. Consequently, the only limitations which should be placed uponthe scope of the present invention are those that appear in the appendedclaims.

What is claimed is:
 1. A method for treatment of a varicose vein comprising the step of applying to the skin of the subject to be treated a device comprising: (a) means for securing said device to the leg of a subject superficial to said vein to be treated; and (b) means for applying a selected amount of pressure to the skin superficial to said vein to be treated in a manner such that blood-flow toward the heart is permitted during peripheral venous pumping but wherein backflow away from the heart as a result of gravity is substantially reduced; and applying sufficient pressure to the skin superficial to said vein to be treated in a manner such that blood-flow toward the heart is permitted during peripheral venous pumping but wherein backflow away from the heart as a result of gravity is substantially reduced wherein the means for securing the device to the leg of the subject is an adhesive means and the device applies from about 0.05 to about 2 pounds of force to the skin superficial to the vein to be treated.
 2. The method according to claim 1 wherein said device further comprises a base attached to said securing means capable of traversing the skin superficial to said vein to be treated in a manner in which substantial downward pressure is not applied to the skin superficial to said vein to be treated.
 3. The method of claim 1 wherein the device is applied superficial to the saphenous vein immediately upstream of the saphenous junction.
 4. The method of claim 1 wherein the device is applied superficial to the saphenous vein immediately upstream of the popliteal junction.
 5. A method for treatment of a varicose vein the step of applying to the skin of the subject to be treated a device comprising: (a) means for securing said device to the leg of a subject superficial to said vein to be treated; and (b) means for applying a selected amount of pressure to the skin superficial to said vein to be treated in a manner such that blood-flow toward the heart is permitted during peripheral venous pumping but wherein backfloyw away from the heart as a result of gravity is substantially reduced; and applying sufficient pressure to the skin superficial to said vein to be treated in a manner such that blood-flow toward the heart is permitted during peripheral venous pumping but wherein backflow away from the heart as a result of gravity is substantially reduced and wherein said means for applying pressure comprises a first surface disposed toward the heart and a second surface disposed away from the heart and said means displaces the proximal wall of the vein toward the distal wall of the vein to form a junction closing the vein, and wherein the angle of the first surface from the plane of the vein is greater than the angle of the second surface from the plane of the vein such that venous pressure on the side of said junction distal from the heart exerts greater effective force displacing said means than does venous pressure on the side of the junction proximal to the heart.
 6. The method according to claim 5 wherein and the device applies from about 0.05 to about 2 pounds of force to the skin superficial to the vein to be treated. 